On 27.11.2025 14:44, Alejandro Vallejo wrote: > On Thu Nov 27, 2025 at 2:19 PM CET, Jan Beulich wrote: >> On 27.11.2025 13:36, Alejandro Vallejo wrote: >>> On Thu Nov 27, 2025 at 10:43 AM CET, Jan Beulich wrote: >>>> On 26.11.2025 17:44, Alejandro Vallejo wrote: >>>>> --- a/xen/arch/x86/Kconfig.cpu >>>>> +++ b/xen/arch/x86/Kconfig.cpu >>>>> @@ -19,4 +19,49 @@ config INTEL >>>>> May be turned off in builds targetting other vendors. Otherwise, >>>>> must be enabled for Xen to work suitably on Intel platforms. >>>>> >>>>> +config HYGON >>>>> + bool "Support Hygon CPUs" >>>>> + depends on AMD >>>>> + default y >>>>> + help >>>>> + Detection, tunings and quirks for Hygon platforms. >>>>> + >>>>> + May be turned off in builds targetting other vendors. Otherwise, >>>>> + must be enabled for Xen to work suitably on Hygon platforms. >>>>> + >>>>> + >>>>> +config CENTAUR >>>>> + bool "Support Centaur CPUs" >>>>> + depends on INTEL >>>>> + default y >>>>> + help >>>>> + Detection, tunings and quirks for Centaur platforms. >>>>> + >>>>> + May be turned off in builds targetting other vendors. Otherwise, >>>>> + must be enabled for Xen to work suitably on Centaur platforms. >>>>> + >>>>> +config SHANGHAI >>>>> + bool "Support Shanghai CPUs" >>>>> + depends on INTEL >>>>> + default y >>>>> + help >>>>> + Detection, tunings and quirks for Shanghai platforms. >>>>> + >>>>> + May be turned off in builds targetting other vendors. Otherwise, >>>>> + must be enabled for Xen to work suitably on Shanghai platforms. >>>>> + >>>>> +config UNKNOWN_CPU >>>>> + bool "Support unknown CPUs" >>>> >>>> "Unknown CPUs" can be of two kinds: Such of vendors we don't explicitly >>>> support, >>>> and such of vendors we do explicitly support, but where we aren't aware of >>>> the >>>> particular model. This needs to be unambiguous here, perhaps by it becoming >>>> UNKNOWN_CPU_VENDOR (and the prompt changing accordingly). >>> >>> Right, what I do in this RFC is have compiled-out vendors fall back onto the >>> unknown vendor path. Because it really is unknown to the binary. >>> >>> I could call it GENERIC_CPU_VENDOR, or anything else, but the main question >>> is whether a toggle for this seems acceptable upstream. I don't see obvious >>> drawbacks. >> >> I'd recommend against "generic" or anything alike, as it'll rather suggest >> any >> vendor's CPU will work reasonably. I'm fine with "unknown", just that the >> nature >> of the unknown-ness needs making unambiguous. > > Got it, if UNKNOWN_CPU_VENDOR sounds better I'm fine with that. > > What are your thoughts on the panic-on-compiled-out-vendor vs use-unknown?
Both have benefits and downsides, I think. The choice may need to be another Kconfig or command line option. I'm also curious what other x86 maintainers may think. Jan
